To meet increasing demands for data traffic, in a current Wi-Fi (wireless fidelity) standard, wider channels and advanced physical layer technologies are used, for example, OFDM (orthogonal frequency division multiplexing) technology and MIMO (multiple-input multiple-output) technology are used to increase a data transmission rate at a physical layer. With development of technologies, a data rate at the physical layer becomes increasingly high. However, the increased data rate at the physical layer decreases data-occupied time, resulting in significantly decreased data throughput efficiency.
To resolve the decreased data throughput efficiency, in the prior art, multiple conventional frames are generally aggregated into one long frame before being sent. A transmit end in an OFDM-based wireless system aggregates frames to be sent to different receive ends into one long frame at the transmit end for transmission, and adds a preamble corresponding to each subframe into a preamble or frame at a physical layer, so that the different receive ends can correctly receive corresponding subframes.
However, in the prior art, after a receive end obtains channel estimation according to a data packet header of a frame, because a longer frame takes longer frame receiving time and a transmission channel varies with time, when a long frame is received, the channel estimation obtained according to the data packet header cannot accurately reflect a transmission channel status due to longer time, resulting in an error in data transmission.